The invention relates to a floor treatment system with a self-propelled and self-steering floor treatment unit, which comprises an electrically driven floor treatment assembly and also a rechargeable power supply unit, and with a central charging station for recharging the power supply unit, the charging station having a transmitting device for emitting an infrared target radiation, and it being possible for the target radiation to be sensed in a directionally dependent manner by a receiving device of the floor treatment unit for the automatic alignment and positioning of the floor treatment unit at the charging station.
By means of such floor treatment units, a floor surface can be treated, in particular cleaned, without it being necessary for an operator to move the floor treatment unit across the floor surface to be treated. Instead, the floor treatment unit is configured in such a way that it automatically travels across the floor surface to be treated in accordance with a predeterminable control program and thereby treats the floor surface by means of the floor treatment assembly. To supply it with power, the floor treatment unit has a rechargeable power supply unit, which is gradually discharged during the treatment of the floor surface. The charging state of the power supply unit is monitored by an electrical control system of the floor treatment unit, and if the charging state falls below a lower limit value, the floor treatment unit steers automatically toward the associated central charging station, which has a power source for recharging the power supply unit. Once recharging has taken place, the floor treatment unit can continue with the treatment of the floor surface.
In order to ensure that the mobile floor treatment unit finds the way to the central charging station and can steer toward it automatically and position itself with respect to it, an infrared target radiation is emitted by the transmitting device of the charging station. While it is traveling across the floor surface, the floor treatment unit comes into the area of the target radiation, which is sensed in a directionally dependent manner by a receiving device of the floor treatment unit, so that it can align itself on the basis of the target radiation received and steer toward the charging station. It has been found that the alignment and positioning of the floor treatment unit does not take place reliably in all cases.
EP 11 72 719 A1 discloses a floor treatment system with a self-propelled and self-steering floor treatment unit and a central charging station, it being possible for the central charging station to generate a first, widely distributed target radiation by means of a first transmitting unit and a second, focused target radiation by means of a second transmitting unit. The second target radiation extends only over a short region and serves for the alignment of the floor treatment unit with respect to the charging station, while the first target radiation reaches further and is widely distributed.
It is an object of the present invention to develop a floor treatment system of the type stated at the beginning in such a way that the floor treatment unit can reliably steer toward the central charging station even when it is relatively far away.